Evaporative Cooling System

ABSTRACT

An improved evaporative cooling system with an enclosed insulated chamber having an inlet, an outlet and a blower in the system located downstream of the outlet to draw air to be cooled through the chamber. A foraminous filter extends across the inlet to clean the incoming air of large solid particles. An electric motor is mounted partially across the inlet opening, having a rotating shaft and supporting a disc for rotation on the shaft. A reservoir of water chilled to between about 55 and 40 degrees Fahrenheit is supported within the bottom of the chamber and positioned for engagement by the disc during rotation, which upon rotation flings chilled water adhered droplets upwardly away from the reservoir in a fan-shaped pattern to further clean, cool and humidify the air which passes through a fog-like curtain formed by the chilled water droplets moving within the chamber, prior to exiting the chamber.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority from U.S. Patent Application Ser. No. 60/953,923 filed Aug. 3, 2007, the entire subject matter of which is incorporated herein by reference.

FIELD OF INVENTION

This invention relates generally to air cooling and conditioning systems, and more particularly to an evaporative air cooling and conditioning system with improved cooling efficiency.

BACKGROUND OF THE INVENTION

The use of evaporative air cooling and conditioning systems is well known. A variety of devices and systems are disclosed, for example, in U.S. Pat. Nos. 3,798,881; 3,948,627; 4,299,601 and 4,640,696; the subject matters of which are each hereby incorporated herein by reference. Alternative evaporative cooling devices are also available which make use of high absorbent, cellulose Kraft paper, especially made for cooling applications, where paper sheets are individually formed and impregnated with thermosetting resins and additives to resist degradation. Such cooling pads are available, for example, from Munters Corp. These various prior art devices and systems disclose air handling units, and in particular, air cooling and conditioning units.

While such systems have provided desired cooling, increased efficiency is desired, particularly in dry and hot climates. In such climates, air cooling is particularly critical. Often, cooling systems are installed on the roof of the facility to be cooled. While the water initially supplied to such systems may have been approximately 70 degrees Fahrenheit, during the heat of the day, the overall and internal temperature of such rooftop systems increases, as does the temperature of any water stored within the system.

SUMMARY OF THE INVENTION

The present application improves prior cooling systems and enables increased cooling as great as 7 degrees Fahrenheit below wet bulb temperature. In the prior systems, air was generally cooled to 80-90% efficiency to wet bulb depression. The cooling advantage of the present improvement provides temperatures at least 7 degrees Fahrenheit below wet bulb temperature. To obtain the additional cooling efficiency, water, which is generally provided to such systems when removed from municipal water supply at approximately 70 degrees Fahrenheit, is provided to a system reservoir, and is cooled to between about 55 and 40 degrees Fahrenheit temperature using a refrigeration system. Cooler water is found to evaporate more slowly, and assists in the overall efficiencies obtained by the improved system. Additional insulation surrounding the water reservoir and system further assists in obtaining the desired system efficiency. Comparable advantages may likewise be obtained in an evaporative heating system, where during winter months, water is heated within the reservoir, rather than cooled.

BRIEF DESCRIPTION OF THE DRAWINGS

There are shown in the drawings, embodiments which are presently preferred, it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown.

FIG. 1 illustrates a schematic top, cut-away view of the improved evaporative cooling system of the present application;

FIG. 2 illustrates a schematic side, cut-away view of the improved evaporative cooling system of the present application, as taken along the line 2-2 of FIG. 1;

FIG. 3 illustrates a schematic end, cut-away view of the improved evaporative cooling system of the present application, as taken along the line 3-3 of FIG. 1; and

FIG. 4 illustrates a schematic end view taken along the line 4-4 of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present application provides an improved evaporative cooling system 10. As illustrated in FIG. 1, the system 10 includes an enclosed chamber 13 having inlets 12. The chamber 13 includes a water reservoir W, an atomizing water distribution assembly 40, and a refrigeration assembly 41 for cooling the water within the reservoir W. An outlet 16 and a blower 18 within the system are located downstream of the inlet 12. The blower 18, an industrial duty, squirrel cage or drum, type blower with an ODP motor M, draws gas through the chamber 13. It is noted in FIG. 1 that an optional second chamber 13′, substantially identical to chamber 13, may be located spaced from the first chamber 13, depending on the desired output of the system. As aspects of the system relative to chamber 13′ are substantially identical, only differences will be discussed further.

A foraminous wall or filter 22, in the preferred embodiment a filter material, such as Paratex, of the type manufactured by Blocksom Corp. of Indiana, extends within galvanized steel frames or channels 56 and slides in and out for ease of maintenance, across the inlet 12, and cleans the incoming gas or air of large solid particles. It is understood that the supply of gas or air is provided from the immediate environment surrounding the location of the system 10. So, for example, where the unit is mounted on the rooftop of a facility to be cooled, the gas supply is outside air. Where the system is suspended from a facility ceiling, inside gas or air is supplied. After the gas or air passes through the inlet 12 past the first foraminous wall filter 22, it is further cleaned, cooled and humidified by the atomizing water distribution assembly 40, which forms a fog-like curtain of water droplets within the chamber 13.

The curtain of water is formed by the atomizing water distribution assembly 40, or slinger wheel assembly, which includes a rotating disc 44 (counterclockwise at about 1,700 RPM) which flings droplets of water from an open-topped water reservoir W formed in the bottom of the chamber 13. An electric motor 32, covered by a housing 42, is mounted on a platform 34 positioned off center from the middle of the inlet opening 12, as shown in FIGS. 1-3, and it rotates the disc such that the disc dips into the reservoir of water W having a consistent water level 24 in the bottom of the chamber and upon rising out of the water flings the adhered droplets upwardly in a fan-shaped pattern. The disc 44 is mounted on a shaft 46 of the electric motor 32 as shown in FIG. 3. Power cable 36 supplies power to the motor 32 and pump 50. Details of the prior system are described in the incorporated patents, as well as in the attached drawings.

The water within the reservoir W is chilled or refrigerated to between 55 and 40 degrees Fahrenheit by a refrigeration assembly, including a sump pump 50, a refrigeration unit 49 and a heat exchange unit 51. The pump 50, where of a water resistant variety, may be positioned on the floor of the reservoir W within the chamber 13. The pump used may be a submersible sump pump of the appropriate application size and type manufactured by the Little Giant Pump Co., Oklahoma City, Okla. The pump 50 provides water from the reservoir W to the heat exchange unit 51 and back to the reservoir, and is mounted by a bracket to the wall 38 of the chamber 13, as shown in FIGS. 1 and 2.

The preferred heat exchange unit 51 is an FP series FlatPlate® heat exchanger of the type manufactured by GEA FlatPlate, Inc. of York, Pa. The heat exchange unit, which is of totally sealed 316L stainless steel plates and copper brazed with a heat transfer surface, is supplied with isolated inlet water from the reservoir via the pump, as well as incoming and isolated coolant material from the refrigeration unit 51. Heat is transferred from the warmer reservoir water to the heat transfer surface, which is cooled by refrigerant or cooling material supplied by the refrigeration unit 49. The refrigeration unit 49, which is supported on a platform above the water reservoir, may be a Copeland brand condenser unit 49 b with a cooling fan 49 a, of the type manufactured by Emerson Climate Technologies, Inc. of Sidney, Ohio. Refrigerant material is circulated to and from the heat exchange unit 51 from the condenser unit 49 b for cooling of the heat transfer unit. The cooling fan 49 a supplies air as indicated in FIG. 2 to cool the condenser unit. Water within the reservoir W is cooled to the desired temperature throughout the day, in order to maintain the desired gas or air exiting the system at the desired temperature.

Downstream of the rotating disc 44 are second filter 48 and, optionally, a third foraminous filter 52. The second or “wet” foraminous wall filter 48 is designed to prevent the entrainment of large droplets of water in the stream of gas or air exiting the chamber through the outlet. Large droplets will impinge on the second foraminous wall and will trickle down the surface and be returned to the open topped chilled water reservoir. The use of a third foraminous wall filter 52 tends to further mix the gases to make a more homogeneous mixture at the point that the gases exit the chamber. Access to the filers 48, 52 is provided via hinged, gasketed, access doors 58 having handles 60.

To ensure that water does not collect around the second and third foraminous wall filters, they are supported on an inclined surface 54 which slopes at an angle toward the open water reservoir. To allow easy passage of water which has trickled down the foraminous wall filters, the lower surfaces of the second and third foraminous walls are supported in relatively short U-shaped channels 56.

To maintain a proper dispersion of water in the fan-shaped curtain sprayed by the rotating disc, it is necessary to maintain the level of the water 24 in the open reservoir W at a relatively constant elevation. As a consequence, level controls are provided in the system for controlling the elevation of the water. Preferably a conventional, mechanical float valve 30 may be used, as well as an electronic water level sensor, which automatically provide water to the reservoir W. Also, an overflow pipe 26 is threaded into a drain connection 28. The level controls may be removed or disabled to drain the system at such time as it is desired to move the apparatus or repair some equipment. To drain the system, the pipe 26 is unscrewed from the drain outlet 28 and water flows out of the reservoir.

The cooling aspect of the invention obviously relates to the summer months. In the heating season the same apparatus may be used to heat air for distribution through the same duct work. Likewise, water within the reservoir may be heated to a higher temperature to increase heating efficiency. The ultimate use of the conditioned air or gas is not material to this invention.

Additional improvements to the system described include providing insulation material R, such as conventional foam or fiberboard R7 rated material, on external surfaces of the chamber housing the refrigeration assembly described above and shown in FIGS. 1 and 2. Improvements to the present system 10 enable the water temperature efficiencies previously described. As water resources are becoming increasingly critical, particularly in dry and hot climates, efficient use of scarce water and energy resources to obtain desired cooling is particularly critical. As previously mentioned, the improvements take advantage of the fact that the water provided to the system is generally removed from ground wells or city water supplies at approximately 65 degrees Fahrenheit. As a result, the already chilled water, is maintained at a cool temperature using the present refrigeration assembly. Cooler water has been found to evaporate more slowly, which results in the overall efficiencies obtained by the improved system 10.

The following examples further describe the prior art and the invention but, of course, should not be construed as in any way limiting its scope.

EXAMPLE 1 Prior Art Example

During a first test protocol, outside air entering into the system (EAT) was measured at 76 degrees Fahrenheit dry bulb. Without operation of the refrigeration assembly, the prior art evaporative cooling system used water in the reservoir measured at 69 degrees Fahrenheit. After operation of the system for 15 minutes, the temperature of air leaving (LAT) the system was 68 degrees Fahrenheit dry bulb. The prior art system was able to reduce the dry bulb temperature by 8 degrees Fahrenheit.

EXAMPLE 2 Present Application Example

During a second test protocol, outside air entering into the system (EAT) was measured at 77.1 degrees Fahrenheit dry bulb. During operation of the refrigeration assembly of the present application, the improved evaporative cooling system used chilled water in the reservoir measured at 37 degrees Fahrenheit. After operation of the system for 15 minutes, the temperature of air leaving (LAT) the system was 64.9 degrees Fahrenheit dry bulb. Thus, the present system was able to reduce the dry bulb temperature by 12.2 degrees Fahrenheit.

EXAMPLE 3 Present Application Example

During a third test protocol, outside air entering into the system (EAT) was measured at 77 degrees Fahrenheit dry bulb. During operation of the refrigeration assembly of the present application, the improved evaporative cooling system used chilled water in the reservoir measured at 49 degrees Fahrenheit. After operation of the system for 30 minutes, the temperature of air leaving (LAT) the system was 64 degrees Fahrenheit dry bulb. Thus, the present system was able to reduce the temperature by 13 degrees Fahrenheit.

The test protocols indicate the ability of the present system to enable increased cooling as great as 5-7 degrees Fahrenheit below wet bulb temperature. It is believed that the use of chilled water between about 55 to 40 degrees Fahrenheit provides a range of improved system cooling performance over the use of water having a temperature of about 70 degrees Fahrenheit or higher.

All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

The use of the terms “a” and “an” and “the” and similar references in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context. 

1. An improved evaporative cooling system comprising, an enclosed insulated chamber having an inlet, an outlet and a blower in the system located downstream of the outlet to draw gas through the chamber; a foraminous filter extends across the inlet to clean the incoming gas of large solid particles; an electric motor mounted partially across the inlet opening, having a rotating shaft and supporting a disc for rotation on the shaft; a reservoir of chilled water supported within the bottom of the chamber, positioned for engagement by the disc during rotation, which upon rotation flings chilled water adhered droplets upwardly away from the reservoir in a fan-shaped pattern to further clean, cool and humidify the gas which passes through a fog-like curtain formed by the chilled water droplets moving within the chamber, prior to exiting the chamber.
 2. The system of claim 1, wherein the temperature of air exiting the chamber is between 5-7 degrees Fahrenheit below wet bulb temperature.
 3. The system of claim 1, wherein the water within the reservoir is chilled to between 55 and 40 degrees Fahrenheit.
 4. The system of claim 1, wherein the temperature of air exiting the chamber is as great as 7 degrees Fahrenheit below wet bulb temperature
 5. The system of claim 1, wherein the gas cooled within the system is room or outside air.
 6. The system of claim 1, wherein the foraminous filter is a polymer material.
 7. The system of claim 1, wherein the enclosed insulated chamber includes a refrigeration assembly, a heat exchange unit and a pump for supplying water from and to the reservoir to the heat exchange unit, having coolant material which is cooled by the refrigeration assembly.
 8. The system of claim 1, wherein the pump is positioned on the bottom of the reservoir submersed within water.
 9. An improved evaporative cooling system comprising, an enclosed insulated chamber having an inlet, an outlet and a blower in the system located downstream of the outlet to draw air to be cooled through the chamber; a foraminous filter extends across the inlet to clean the incoming air of large solid particles; an electric motor mounted partially across the inlet opening, having a rotating shaft and supporting a disc for rotation on the shaft; a reservoir of water chilled to between 55 and 40 degrees Fahrenheit is supported within the bottom of the chamber, positioned for engagement by the disc during rotation, which upon rotation flings chilled water adhered droplets upwardly away from the reservoir in a fan-shaped pattern to further clean, cool and humidify the air which passes through a fog-like curtain formed by the chilled water droplets moving within the chamber, prior to exiting the chamber.
 10. The system of claim 9, wherein the enclosed insulated chamber includes a refrigeration assembly and a heat exchange unit for chilling the water within the reservoir.
 11. The system of claim 10, wherein the enclosed insulted chamber further includes a pump for supplying water between the reservoir and the heat exchange unit.
 12. The system of claim 11, wherein the pump is positioned on the bottom of the reservoir submersed in water. 